Diffractive security element having an integrated optical waveguide

摘要

A diffractive security element ( 2 ) is divided into surface portions, having an optically effective structure ( 9 ) at interfaces embedded between two layers of a layer composite ( 1 ) of plastic material. At least the base layer ( 4 ), which is to be illuminated, of the layer composite ( 1 ) is transparent. The optically effective structure ( 9 ) as a base structure has a zero order diffraction grating with a period length of at most 500 nm. In at least one of the surface portions an integrated optical waveguide ( 5 ) with a layer thickness (s) of a transparent dielectric is embedded between the base layer ( 4 ) and an adhesive layer ( 7 ) of the layer composite ( 1 ) and/or a protective layer ( 6 ) of the layer composite ( 1 ), wherein the profile depth of the optically effective structure ( 9 ) is in a predetermined relationship with the layer thickness (s). Upon illumination with white incident light ( 13 ) the security element ( 2 ) produces light ( 14 ) which is diffracted in the zero diffraction order, of high intensity and with an intensive color.